This application is related to a copending application entitled "Autonomous Radio Timepiece Having a Resettable Receiver Actuation Switch" in the name of the present inventor, filed on or about the date of filing of the present application.
1. Field of the Invention
The present invention concerns an autonomous radio timepiece having a time display which may be set to a predetermined initial position by means of a START switch actuating a receiver.
2. The Related Art
A radio timepiece of this type is known from the article by W. Ganter "JUNGHANS Radio Timepiece RC 2" in Goldschmiede-Zeitung No. 1/1988, page 148. This radio timepiece which within a short period of time attained market leadership, activates the receiver periodically temporarily, at predetermined points in time, in order to correct the instantaneous time display, if necessary, to reflect the time received in a radio transmitted time telegram. Independently, the receiver may be turned on by actuating a reset or START switch, whereby the instantaneous time display is simultaneously set to the 00:00:00 H reference position. As soon as valid time information is received by radio, the receiver is deactivated and the time display is rapidly set to the corresponding position. If it is necessary to move mechanical parts (hands or digital drop disks) in the process, the time required for this operation is taken into consideration in the setting, so that the actual instantaneous time is correctly displayed.
However, a problem may be caused by the fact that the time information transmitted by the radio station relates to a certain geographic time zone. In the case of a portable time piece, for example, a wristwatch or an alarm clock, the display on the timepiece will no longer be correct relative to the hour, if the traveller passes the boundary of a time zone. In these cases, because of the new time zone, the indication of the hour may be earlier or later by at least one hour (or depending on the state of the time zone, by one-half hour).
There arises an even more severe problem if a radio timepiece of this particular generic type is to be actuated, but due to local conditions at the given location no correct time telegrams can be received. This may occur, for example, due to poor receiving conditions, or the operating state of the sender, for example, a station which is deactivated instantaneously or possibly until further notice. However, users can expect that a high technology product, such as a user radio timepiece, would be usable as a timepiece even under such exceptional conditions specific to radio.
SUMMARY OF THE INVENTION
In view of these conditions, it is the object of the present invention to overcome the aforementioned disadvantages.
It is a further object of the present invention to equip a radio timepiece of a generic type so that it may be operated even after a change of time zones, without receiving time telegrams set for the new time zone, with the correct display of time.
It is a further object of the present invention to operate a radio timepiece as a timepiece of conventional accuracy even if, at any given moment, no evaluable time telegrams may be received.
These objects are attained essentially by a radio timepiece that is equipped with an hour switch for allowing the modification of the hour display.
The solution according to the present invention is thus based on the discovery that it is sufficient, in the case of a correctly indicating radio timepiece, to correct the existing hourly indication one time manually (that is, set it ahead or back) after a change in the time zone, whereupon, in the future, this time zone correction will be automatically taken into consideration in the radio controlled time display. For this, the time zone correction value may be entered manually into a separate hour memory, from which the correction value (with reference to the accompanying addition or subtraction sign) is combined with the decoded hour information actually received from the sender, which is set for another time zone, for the display of the actual local time. In this manner, radio controlled operation is possible even outside the time zone for which the sender is set. If the traveller returns to the time zone for which the sender is correct, the previous zone correction may be cancelled either by setting the additional zone hour memory manually to zero, so that no zone correction is added to the hour information received by radio, or by restarting the radio timepiece by actuating the reset key, whereby the hour correction memory is simultaneously set to zero.
The present invention makes it possible further to await, in order to activate the timepiece without the instantaneous receipt of valid time telegrams in a conventional manner, the synchronizing signal sent out, for example, by radio stations at full hours, and then to actuate the reset or START switch. The time display is thereby reset to 00 minutes and 00 seconds and the timepiece started under an internal time basis for the continued display of time, but with an arbitrary incorrect (randomly entered) indication of the hour, or the hour 00, if the hour display has also been sent to 00 by the reset switch. The hour display is corrected together with the actualization of the rest of the instantaneous time display, if a valid radio time telegram is received. If this does not occur within a reasonable period of time, then, as in the case of a change in time zones, a manual correction of the obviously incorrect hour display is carried out by setting the additional hour memory. Based on this correction information, the hour display is then continued by the internal time basis. If subsequent thereto, occasions should arise in which time telegrams may be received and decoded, the hour memory associated with the receiver (in the display register) is set to the sender hour and the hour memory associated with the hour switch must be corrected correspondingly, so that the hour displayed again corresponds with the local geographic conditions.
Similarly to situation of the adjustment of the instantaneous time display to the actual prevailing time, it is also true for the zero setting of the time display by actuating the reset or START switch that the adjustment of the display may be carried out practically without inertia, if the time display is nonmechanical, i.e., for example an electronic display for the display of stepping hand or digital symbols. However, the solution according to the present invention may also be applied to mechanically stepping time displays (e.g., gear driven hands or other mechanical displays, such as digital drop disks). In these cases, it is merely necessary to take into consideration, by means of an appropriate correction, in a manner known in itself, the time delay involved for the movement from the instantaneously given display position into the 00 reference position, when, upon the appearance of the hour synchronizing mark, the START switch was activated. The time keeping stepping movement of the display then takes place from the internal time basis, as soon as the instantaneous display has reached the actual prevailing time.
Still other objects, features and attendant advantages of the present invention will become apparent to those skilled in the art from a reading of the following detailed description of the embodiments constructed in accordance therewith, taken in conjunction with the accompanying drawings.